Telephone-repeater.



P. STRAGIOTTI.

TELEPHONE RBPEATER.

APPLICATION FILED we, 11, 1908.

Patented Apr. 5, 1910.

ammntov Q/vihwono subject of the King of Italy,

UNITED STATES PA'rENT OFFICE.

PIETBQ STBAGIOTTI, 0F HUB-LEY, WISO0N$IN, ASBIGNOB OF ONE-NURTH T0 GpIFElTH THOMAS, ONE-FOURTH T0 JOSEPH MARTA, ALL 015 HUBLEY, WISGONSIN.

VERGELLI'NI, AND ONE-FOURTH TO FRANK TELEPHONE-BEPEATEB.

Specification of Letters Patent.

Patented Apr. 5, 1910.

Application filed August 11, 1908. Serial No. 8,023.

To all whom it may concern:

Be it known that I, Pizarro STRAGIOTTI, residing at Hurley, in the county of Iron and State of Wisconsin, have invented certainnew and useful Improvements in Telephone-Reeaters' and I do declare the followingto e a full, clear, and exact description of the invention, such as will enable others skilled inthe art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon, which -orm a part of this specification.

My in :ention relates to the class of telephony, and consists in the system of connection of two micro-translators at am intermediate station with the two parts of a line with only two wires (one of thewires may be surrogated by the ground) so that every micro-translator has control of only one line; that is to say that the division of the current generated by one micrortrans Iator is obtained in two parts always equal,

so that the two points where the othermicrotranslator is bridged there is always elec-,

tric equilibrium.

My invention further consists in certain other novel details of construction" and in combinations of parts, all of which will be first fully described and afterward specific;

pointed out in the appended claims.

all

fieferrlng to the accompanying drawingzj Figures 1 2, 3 and! illustrate specific systems of wlring.

Like characters of'reference indicate the induction, so that the said current cannot undergoany sudden. sensible 't ariation of its medium value. i r B indicates the but I and M is the micro-receiver and '1, an ,1 are the two The current coming fromfthe battery, passes thr h the inductive reactance', goes to the centre electrode of the micro-rece ver where reache faction it forks, each branch passing through the primary of the transformer. As the two transformers are equal, so result two ident cal derived circuits. The secondaries are connected at the same end oP0, and in this way result in series therefore to any induct onin the same direction on the two pri- 1n ar1es,.1nducti0n forces in the opposite direction corresgiond on the secondaries, so that to the'equa increasing or diminishing of the current in the-two rimaries the secondary induction current mes zero, hut when under the influence of the micromecei ver M the comparative relation of the two primary currents varies by the increasing f the o e and the equal contempo ary dim nishing of the other (which must happen under the effect of an inductive reactance of sufiicient energy) then there are indil ti n. es, i the condary which sum g t r, nd a curren is produc d in the sand secondary proportionedto the variation of h infe e e which is forming between h t o prim ry cu r n s Only ne ansf m r may be instee 015 tw h s prim ries in m sgi so hat they are neutralr. under equal ur en s but. two d s mct tran form: are pref when distinct the is lways magnetize in the same ic nsonant. the magn tic pennanblhty is m re near-1 constant allowing a mom co r ct ra smission of the were to the modern- The oscil ating current ich pa es in the has L makes the die ph f he micro-WW1 or. microtra ator' vlbragte, 'prodl} arlatlpn resis ances in t e two parts at the m ero-phone, and the p oduction of new oscillating currents in the secondary clmuit of the transf rmers will be the final efiect, the said currents be ng entirely anal gous to the currents coming from the ciru t L, but much more energetic Therefore p i n make the dmphragm o e micro-receive vibrate. When an oscillatory current s fl n h ugh the coil the ac ion i t change difiemntlelly the pressure between the middle electrode andhe other two. The

cha ge of in the two derived "currents In be heard with this disposition,

hey are suflie ently energeti to instance I term a*micro-trafn cuits which fork at the V microphone being difl'erential such will be the variations of the towing currents, and diflerential will be the variations of these currents. If these changes of resistance do not ex com pensate each other then the balance acts as to. make the main current oscillate while it is intended to remain constant. Therefore the auto-induction coil by opposing such oscillations of the main current acts 1n a manner that the microphone acts strictly as differential. N ow the two transformers being alike, it is clear that when in the rimary coils the current is undergoing di erential chan s, viz., increasing in the one .while diminis 'ng in the other e. m. f. of induction are produced in the secondary coils, alike but opposite. But establishing the connections of the secondary coils as "those are .in Fi 1 these same e. m. f. sum together and 0e05- latory current flows therefore in the secondary circuit. In the drawing it is sup sed e jliile that the two transformers are alike.

Ris pointed out in a direct way that the connection of one of the secondary coils is the inverse yet it is clear that the same resuit can be obtained b changing the direc tion of the winding'of one coil without inversion of any connection.

Referring now to Fig. 2 we will conside that B is the farthermost station from' A where it is possible to hear clearly. If at B a micro-receiver is placed which ,in this slator, new electric oscillatory curmntawith the same energy as the original current in A are produced and are therefogeable to reach C,- said new electric oscillatorycurrents being roduced in the new line 'Hto' 1C. ll ore than one of 'the translators-can be 1 and thereby the length of the telephonic line will be very much increased according to the number of translators employed. To"

be certain of the correct action, two so rated lines are needed, namely, one carrying the voice from A to O with translation in B where the micro-translator is under the influence of the line A- B, while the con nected transformers command the line B-O, and another independent line which carries the voice from C to A with a special microtranslator in B under the influence of the line and commanding the second line B-A. c 3

A special disposition of the electric cir-' cuits has been found (Fig. 4) by which the passing of the telephonic currents indiifer: ently an both directions is obtained with only two wires without the danger that a current coming forinstance, from the first line and trans erred to the second may by the micro-translator under the command of the secondline act agam onlthe first line can electric oscillations able to interfere witl l tifie proper ones. In this figure L and tcdines from O through I, B to C01 other L are the two branches of the line which end at the station where the micro-trans latorsare laced. M and M are the two micro-trans ators respectively under the infiuence of the line L and ofithe line L In 0, I, B, P, Q or R and 0 there is the local circuit through the micro-phone M, the battery B, the inductive reactance I and the two transformers T and T. In 0 1 1351, Q or R and 0 there is a local circuit throu h the micro-phone of M the battery B, t e inductive reactance I and the two transformers T and T.

Instead of the two batteries B and B and the two reactance coils I and I only one battery B and onereactance. coil I of sufiicient ener may be employed, sup ressin the circuits 0, I, B- and "and 6 I, 2 and I" and usin instead the circuits indicated b doti an from P through the dotted line to P by which the same effect will be obtained. The lines L and L lead to the two transformers K, and K The transformer K is exactly equal to the transformer K and the transformer K, is exactly equal to the transformer sistance, capacity and induction, respectively of the hue L, and as for the circuitL the oscillatory current passing through them.

and coming from the oints :11 audio at the middle of each doub e coil must divide in two equal parts as for the phase and inten- ,K ;and as for the circuit L the same rei sit because the self induction of the one is suppressed by the induction of the The micro-translators are bridges between the two ends Y and Z and Y and Z of E and E; If there is any oscillate current on the line L the said current wil produce another os'cillato current in the microtranslator circuit Y D and Z so that the micro-phone M is working and willptoduee an oscillatorycurrent o much eater energy in the secondary S. The sa1d current will divide at as into two equal parts in intensity and of the same %h ase in the two circuits X, Z, I) and X, D to join in D, and two oscillatory currents equal-in phase and in intensity will be produced in the two circuits L and L by means of the As to the two transformers K and K. currents circulating in the two branches X,

Z, D and X, Y, D are equal and acting exactly in the same way omthe two parts because they are alike in everything, acti forces, and work done the two arts Y an Z on which'themicro-phone is bridged will always be under the same tension. Therefore no current coming from the m1- cro-phone M can circulate between the said two oints so that the micro-phone M will be si ent and will not disturb in any way the acting of the micro-phone M by sending currents to the line L. \Vith this disposition currents coming from the line L will ass without any interference to the line L m the same way the currents coming from the line L will roduce by the micro-phone M currents on the line L acting in the same way. i a Havin thus fully described my invention what I c aim as new and desire to secure by Letters Patent of the United States is;

1. A repeater circuit which divides in two parallel circuits, comprising the primaries of two transformers and two inductance coils established opposite on the same core, a second repeater aving its coil bridged between two corresponding points of said parallel circuits.

2. A repeater circuit which divides in two arallel circuits comprising two inductance coils established opposite on the same core, a second repeater having its coil bridged between two corresponding points of said parallel circuits.

3. A re eater circuit which divides into two para lel circuits comprising two inductance coils established opposite on the same core, a second repeater which has the coil bridged between two corresponding points of said parallel circuits a local circuit through an induction coil, a source of current therefor by means of which the first repeater can act on a telephone line connected with one of the two parallel circuits of two telephone i actly balance without interference upon the second repeater. i

4. In a telephonic system the combination circuits, two repeaters therefor, an intermediate local circuit, a source of current therefor, a special circuit on which each repeater acts by means of said intermediate local circuit, said special circuit dividin in two parallel circuits comprising two inductance coils established opposite on the same core, the coil of the second repeater being bridged between two corresponding points of said parallel circuits, one of which is connected with one of said telephone circuits, and means to exthe other of said two parallel circuits so that thecircuit of the telephonic line which acts upon the first repeater acts upon the other circuit of the telephonic line without any interference with said second re eater. y

5. T e combination of two repeaters, each acting on a circuit which divides in two parallel circuits comprising two inductance coils established opposite on the same core, the coil of one repeater being bridged between two correspondin points of said parallel circuits, a local clrcuit, a source of current therefor b means of which the one repeater acts equa ly on the said two parallel circuits.

In testimony whereof, I aflix my signature, in presence of two witnesses.

PIETRO STRAGIOTTI.

Witnesses:

C. M. Fomms'r, O. HUGH DUFFY. 

